How to Retrieve Specific Data from a SQL Server Database Using C#?

Retrieve Data from a SQL Server Database in C#

When working with a database table containing columns such as firstname, Lastname, and age, retrieving specific data values based on user input can be essential. In this scenario, you have three textboxes in your C# Windows application and have established a connection to a SQL Server database.

To retrieve all other details corresponding to a given firstname value, a parametrized query approach is recommended for security reasons. Here's how you can achieve this:

public Person SomeMethod(string fName)
{
    var con = ConfigurationManager.ConnectionStrings["Yourconnection"].ToString();

    Person matchingPerson = new Person();
    using (SqlConnection myConnection = new SqlConnection(con))
    {
        string oString = "Select * from Employees where FirstName=@Fname";
        SqlCommand oCmd = new SqlCommand(oString, myConnection);
        oCmd.Parameters.AddWithValue("@Fname", fName);
        myConnection.Open();
        using (SqlDataReader oReader = oCmd.ExecuteReader())
        {
            while (oReader.Read())
            {
                matchingPerson.firstName = oReader["FirstName"].ToString();
                matchingPerson.lastName = oReader["LastName"].ToString();
            }

            myConnection.Close();
        }
    }
    return matchingPerson;
}

Explanation:

1. We use a parametrized query ("Select * from Employees where FirstName=@fName") with a parameter named @fName to prevent SQL injection.
2. We create a Person object to store the retrieved data.
3. We execute the query, and if there is a matching record, we populate the Person object with the corresponding values (firstName and lastName).

Usage:

To use this method, you can call it like this:

Person x = SomeMethod("John");

Once you have the data in the Person object, you can assign the values to the textboxes in your application:

txtLastName.Text = x.LastName;

This approach allows you to retrieve all the other details related to a specific firstname value from the database and display them in the corresponding textboxes.

The above is the detailed content of How to Retrieve Specific Data from a SQL Server Database Using C#?. For more information, please follow other related articles on the PHP Chinese website!